JPH0582812B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Field of Application> The present invention relates to a method for producing a rubber laminate in which an FKM layer and an NBR layer are vulcanized and bonded, and is suitable for use in automobile fuel hoses, fuel pump diaphragms, and the like. In this specification, "FKM" is an abbreviation for fluororubber, and "NBR" is an abbreviation for nitrile rubber. Moreover, "PHR" refers to the outer weight percentage relative to the rubber content (polymer). <Conventional technology> FKM has excellent physical properties such as heat resistance, chemical resistance, aging resistance, and cold resistance, and is resistant to oil and fuel.・It is attracting attention as a material for packing materials, etc., but it is 10 to 20 times more expensive than general-purpose rubber such as NBR, and its usage is limited. Therefore, when using FKM as a material for fuel hoses, etc., it is a general-purpose rubber with relatively good oil resistance.
It is conceivable to use the NBR layer as a base layer by vulcanizing and adhering the FKM layer to the side that requires higher physical properties, but in general, the FKM layer and the NBR layer are separated by vulcanization. It was difficult to adhere. In particular, this tendency was particularly pronounced when the FKM layer was composed of a peroxide-cured compound. Furthermore, peroxide-cured FKM has a faster vulcanization rate and higher crosslinking density than other polyamine/polyol-cured FKMs, so it has good compression resistance even without secondary vulcanization. It has advantages such as being able to obtain permanent deformation (settling resistance). Therefore, Special Publication No. 57-49391, Special Publication No. 59-
Publication No. 33304 and other publications propose a method of improving adhesion by incorporating metal oxides such as magnesium oxide and silica into unvulcanized NBR compounds, but the interlayer adhesion between the FKM layer and the NBR layer was not necessarily sufficient. For this reason, the present inventors have developed a peroxide vulcanization FKM formulation containing a vulcanization compound used in a polyol vulcanization system in addition to a peroxide vulcanization compound. and an NBR layer made of an NBR compound containing a metal oxide (if a metal oxide (or hydroxide) is included as a vulcanization aid, in addition to it). A laminate bonded by vulcanization has been proposed (see Japanese Patent Application Laid-open No. 1987-87102). <Problems to be Solved by the Invention> In order to obtain a large interlayer adhesive force between the NBR layer and the FKM layer, the above rubber laminate requires a vulcanization accelerator contained in a polyol vulcanization-based vulcanization compound. Because it is necessary to incorporate a large amount of (organic phosphonium salt/or quaternary ammonium salt), scorch is likely to occur in FKM during extrusion or kneading, and the physical properties of FKM deteriorate, especially solvent cracking resistance and cold resistance. I had a problem with it getting worse. <Means for Solving the Problems> Therefore, in order to solve the above problems, the present inventors made earnest efforts in development, and as a result, the inventors of the present invention have developed a superfluous resin containing a polyol vulcanization-based vulcanization compounding agent. An NBR compound containing an FKM layer consisting of an oxide vulcanization-based FKM compound, a specific amount of a metal oxide, and a specific amount of a vulcanization accelerator in the above-mentioned polyol vulcanization-based vulcanization compound. It has been found that if the rubber laminate of the present invention is vulcanized and bonded with the NBR layer, scorch is less likely to occur in the FKM during production, the physical properties are good, and the resulting rubber laminate has good interlayer adhesion. Completed the method for manufacturing the body. <Embodiment> FKM layer 1 consisting of the following FKM compound <A>,
It is manufactured by vulcanizing and adhering NBR layer 2 consisting of the following compound <B>. Here, the method of vulcanization adhesion is not particularly limited. For example, in the case of a rubber hose as shown in Figure 1, each compound is extruded simultaneously or separately from one or two extruders and laminated, then laminated under appropriate conditions (145-170℃ x 30-90min). ) to perform vulcanization adhesion.
In addition, in the case of a diaphragm as shown in Figure 2,
Each compound is rolled out into sheets, which are then punched out and stacked on top of each other, and then press-molded (mold temperature: 150-190°C, time: 3-30 min, pressure: 50-150 kgf/cm ² ) to perform vulcanization bonding. Note that 3 in the illustrated example indicates the base fabric layer. still,
The configuration of the rubber laminate is not limited to the illustrated example, and can be applied to, for example, reinforced hoses, hoses and diaphragms with FKM layers on the inside and outside (front and back), and even full rubber diaphragms. <A> FKM compound: Consists of the following FKM polymer, peroxide vulcanization type vulcanization compound, polyol vulcanization type vulcanization compound and other auxiliary materials. (1) FKM (polymer) is not particularly limited to binary or ternary type as long as radically active iodine or bromine is introduced into the polymer to enable peroxide vulcanization. Examples of the binary system include vinylidene fluoride/propylene hexafluoride copolymer, and examples of the ternary system include vinylidene fluoride/propylene hexafluoride/ethylene tetrafluoride terpolymer. More specifically, the above are product names such as Daiel G801, and the above are Viton GF, Viton
They are marketed under product names such as GH, Viton VTR5362, Daiel G901, and Daiel G902. Note that "Viton" and "Daiel" are trademarks of DuPont and Daikin Industries, respectively. (2) In addition to organic peroxide as a vulcanizing agent and triallylisocyanurate as a co-crosslinking agent, peroxide vulcanization-based vulcanization compounds can also be used in other vulcanization systems. Also included are acid acceptors such as MgO and inorganic accelerators such as Ca(OH) ₂ . Furthermore, FKM formulations include:
Naturally, reinforcing agents such as carbon black, processing aids, and optionally coloring agents, scorch inhibitors, etc. are blended. Examples of the peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-
2,5-di(t-butylperoxy)hexane-3,1,1-bis(t-butylperoxy)
-3,3,5-trimethylcyclohexane, t
-Butyl peroxybenzoate, etc. can be exemplified, and the amount thereof is usually 1 to 10 PHR. (3) A polyol vulcanization compound is a combination of an aromatic polyol compound as a vulcanizing agent and an organic phosphonium salt and/or quaternary ammonium salt (can be used alone or in combination) as a vulcanization accelerator. It is something that The blending amount of the vulcanizing agent (aromatic polyol) is usually 1.3 to 2 PHR, and the blending amount of the vulcanization accelerator is Mooney scorch time (JISK6300, 145℃) t ₅ for 4 minutes or more, solvent crack resistance. Set the amount so that the resistance is 100 seconds or more and the non-destructive temperature is -20℃ or less. From Table 1, the organic phosphonium salt and organic ammonium salt should be 0.7 PHR or less. The aromatic polyols include hexafluoroisopropylidene-bis(4-hydroxyphenyl)hydroquinone, isopropylidene-bis(4-hydroxyphenyl)hydroquinone,
bis(4-hydroxyphenyl), organic phosphonium salts such as triphenylbenzylphosphonium chloride, tetraphenylphosphonium chloride, tetraoctylphosphonium chloride, quaternary ammonium salts such as triphenylbenzylammonium chloride, tetra- Examples include phenyl ammonium chloride and the like. (4) Other auxiliary materials include carbon black as a reinforcing agent, MgO and Ca(OH) ₂ as acid acceptors,
There are plasticizers and processing aids, which are added as appropriate. <B> NBR compound: A vulcanizing agent and metal oxides selected from Group 1 of the periodic table are blended with the NBR polymer below, along with other auxiliary materials, and the vulcanization accelerator (organic phosphonium salt and/or quaternary ammonium salt) 0.1 to 2 PHR if the organic phosphonium salt is included in the polyol vulcanization compound in the FKM formulation, and 0.05 to 2 PHR if the quaternary ammonium salt is also included.
Contains 2 PHRs. Here, if the blending amount of the vulcanization accelerator is less than the lower limit value, it will be difficult to obtain a large interlayer adhesive force between the FKM layer and the NBR layer, and even if it exceeds the upper limit value, the interlayer adhesive force will not increase and it will be wasteful. be. (1) NBR is an acrylonitrile-butadiene copolymer, but from the viewpoint of oil resistance and cold resistance of the NBR layer, the bonding amount of acrylonitrile is usually 15 to 55.
% is used. Specifically, Nipole
DN101・103・202・302・206, TN103,
JSRN220S/N230S/N231H, hiker
Examples include those labeled with trade names such as 1001, 1031, and 1042. Here, “Nipole” and “hiker” are Nippon Zeon’s “JSR”
are trademarks of Japan Synthetic Rubber. (2) The vulcanization system for this NBR is not particularly limited, such as sulfur vulcanization, peroxide vulcanization, etc. Incidentally, as the peroxide vulcanizing agent, those exemplified above are used. (3) Examples of metal oxides include magnesium oxide,
Examples include aluminum oxide, zinc oxide, zinc dioxide, calcium oxide, lead oxide (,), silicon dioxide, etc., and their hydroxides. Among these, magnesium oxide, calcium hydroxide, aluminum hydroxide, lead oxide, () is preferred. The amount of these metal oxides is usually 5~
It will be 30PHR. (4) Auxiliary materials other than those mentioned above include reinforcing agents such as carbon black, vulcanization accelerators, processing aids, plasticizers, coloring agents, anti-aging agents, etc., and are blended as appropriate. <Effects of the Invention> As described above, the method for producing a rubber laminate of the present invention involves blending a specific amount of a vulcanization accelerator in the polyol vulcanization compound contained in the NBR compound as well as in the FKM compound. By doing so, during production, scorch is less likely to occur in FKM during extrusion, kneading, and calendering, and the physical properties of the material are also good. Furthermore, the interlayer adhesion of the resulting rubber laminate is also good, as shown in the examples below. It is. <Example> For each test example, the FKM layer was prepared using the formulation shown in Table 1, and the NBR layer was prepared using the formulation shown in Table 2.
The layers were rolled into sheets of 4mmt each and heated at 170°C for 15 minutes using the combinations shown in Table 3.
Pressure vulcanization was carried out under the conditions of 150 kgf/cm ² . The adhesive strength is
Measured according to JISK6301 "Peeling test".
In addition, the scorch time (JISK6300, 145℃), normal state physical properties (JISK6301), solvent cracking resistance and low temperature impact embrittlement test (JISK6301) of each FKM and NBR
The results are shown in Tables 1 and 2. Note that solvent cracking resistance was determined using Fuel D (toluene) using a JIS dumbbell No.
60vol%/isooctane 40vol%),
The time until breakage was measured. From the results shown in Table 3, it was found that the vulcanization accelerator in the vulcanization compound of polyol vulcanization is added to NBR at a specified amount or more (0.1 PHR or more when organic phosphonium salt is added to FKM, and quaternary ammonium When salt is added (0.05PHR or more), when salt is added (N-2, 3, 4, 5, 6), FKM
It can be seen that good interlayer adhesion occurs between the layer and the NBR layer. Furthermore, Table 2 shows that even if a polyol vulcanization accelerator is added to NBR, the scorch time is not affected. As shown in Table 1, FKMs F1 to F3 and F6 to F7 all have scorch times of 7 minutes or more.

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[Table] *Rubber destruction

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a rubber hose, which is an example of a laminate to which the manufacturing method of the present invention can be applied, and FIG. 2 is a perspective view of a diaphragm. 1...Fluororubber layer, 2...NBR layer, 3...Base fabric layer.

Claims (1)

[Claims] 1. A method for producing a rubber laminate, which comprises vulcanizing and adhering an FKM layer made of the following compound (A) and an NBR layer made of the following compound (B). (A) A peroxide vulcanization FKM formulation contains a polyol vulcanization compound containing an organic phosphonium salt. (B) In the NBR formulation, the metal oxide (or hydroxide) selected from Group 1 of the periodic table is
50 PHR (in addition to a metal oxide if it is included as a vulcanizing agent) is blended, and 0.1 to 2 PHR of an organic phosphonium salt and/or quaternary ammonium salt is further blended. 2. A method for producing a rubber laminate, which comprises vulcanizing and adhering an FKM layer consisting of the following compound (A) and an NBR layer consisting of the following compound (B). (A) A peroxide vulcanization FKM formulation contains a polyol vulcanization compound containing a quaternary ammonium salt. (B) In the NBR formulation, the metal oxide (or hydroxide) selected from the periodic table group is 5 to 5.
50 PHR (in addition to a metal oxide if it is included as a vulcanizing agent) is blended, and 0.05 to 2 PHR of an organic phosphonium salt and/or quaternary ammonium salt is further blended.